help me plan my exhaust system

[mustanggarage]

I am going to be dropping the engine and the rest of the drivetrain into the chassis next month and I need to start planning my exhaust. I am putting a 351 with an ax 15 and a dana 20 into the chassis. I prefer the sound and look of the magnaflow mufflers. I am trying to plan which exhaust system is going to work the best for me. I have been looking pretty hard at bronco huts system with the shorty headers.

what systems have been used with this setup and what works the best. ?

 

[broncomike629]

I have a 302 and I used some cheapy stainless ebay shorties but I just installed the bronco hut system and although I haven’t fired it yet I was happy with the way it went together (even though there are zero installation instructions). It did take a few weeks to show up though so plan accordingly. Only downside for me in New England is that it is not stainless

 

[broncomike629]

Sorry, is stainless, I have looked at so many options my head broke!

 

[1971BroncoSport]

Duff

I just installed Duff’s long tube headers and dual exhaust with magnaflow. Went in easy. One header bolt on each side was a little tricky - but went in fine. Two pages of instructions that were well written.

 

[mustanggarage]

I just installed Duff’s long tube headers and dual exhaust with magnaflow. Went in easy. One header bolt on each side was a little tricky - but went in fine. Two pages of instructions that were well written.

What engine and transmission do you have

 

[mustanggarage]

Sorry, is stainless, I have looked at so many options my head broke!

Yeah I know how that goes lol

 

[Broncobowsher]

What engine and transmission do you have

Most header flanges will have one hole that is smaller then the rest. That is for alignment. sometimes a hole at the other end will be oval, also for alignment. IF all the holes were just the right size it would be really hard to install, the slightest warp would throw it off. So one hole to set the alignment and all the sloppy holes to hold it in place. Why you always start all the bolts before you tighten any of them down.

 

[mustanggarage]

Most header flanges will have one hole that is smaller then the rest. That is for alignment. sometimes a hole at the other end will be oval, also for alignment. IF all the holes were just the right size it would be really hard to install, the slightest warp would throw it off. So one hole to set the alignment and all the sloppy holes to hold it in place. Why you always start all the bolts before you tighten any of them down.

the reason I'm asking is I want to know how these individual exhaust systems might work with my setup. I am looking to see what clearance issues I might have.

 

[1971BroncoSport]

What engine and transmission do you have

302 and C4

 

[rguest3]

With a change in the drivetrain from stock, I would recommend a local exhaust shop to bend the pipe for you. It will fit. Some of the Exhaust "Kits" may not fit as well.

 

[SDBMtber]

O have a 351 and ax15. Went with the bronco hut shorty headers and their 2 into 1 exhaust system. It seems to fit but there are definite tight spots. Not sure if I ended up with the ideal routing or not. Kit and headers are definitely well designed and made in my opinion.

I had to take about an inch off the end of a couple pieces to get everything lined up as best as possible. Haven’t fired it up yet to evaluate sound or if it’s all sealed up.

Here are some pics during install and layout. Not the final fit I don’t think.

 

[mustanggarage]

O have a 351 and ax15. Went with the bronco hut shorty headers and their 2 into 1 exhaust system. It seems to fit but there are definite tight spots. Not sure if I ended up with the ideal routing or not. Kit and headers are definitely well designed and made in my opinion.

I had to take about an inch off the end of a couple pieces to get everything lined up as best as possible. Haven’t fired it up yet to evaluate sound or if it’s all sealed up.

Here are some pics during install and layout. Not the final fit I don’t think.

that is perfect. can you tell me what and where you had to cut it?, did you weld the o2 sensor bung in, or does it come that way?

 

[mustanggarage]

and btw I am not sold on one kit versus another. I have been looking at that duffs setup pretty hard also. so if anyone has used it on a 351 I would like to see how they fit etc. the main reason I was looking at bronco huts is they specifically say on there web site that it will fit 351 and ax 15.

 

[onpier55]

Call and talk to Monstrr mike at Duff’s. He can tell you what, if any of his setups will fit. They have a rolling chassis that they mock up their systems. I installed the 2into1 setup. I’m happy with it.

 

[SDBMtber]

It came with bungs welded in both the passenger and driver header. I only need to use one. I remember thinking one side (maybe passenger) would be a super tight fit between installed sensor and firewall.

Not at home until Sunday. I can verify more when I’m near the bronco if you want. I don’t remember the cuts unfortunately! I think about an inch off the driver side header tube or crossover pipe. And a couple inches off the muffler outlet pipe I think to position the tailpipe. It pretty much rests on the transmission crossmember and this is the tightest fit. Not sure if that will prove to be a problem or not.

Duff was looking for guinea pigs about two weeks after I bought this setup. If I hadn’t already purchased, I definitely would’ve considered giving their kit and headers a try.

 

[BradinEDH]

Here is what I did. 351W with NV3550. Wh Long tube headers, Magnaflow muffler and Summit tubing. Custom cut and welded in the garage. Had to clearance for the Clutch linkage. Otherwise I love it.

 

[mustanggarage]

Call and talk to Monstrr mike at Duff’s. He can tell you what, if any of his setups will fit. They have a rolling chassis that they mock up their systems. I installed the 2into1 setup. I’m happy with it.

It came with bungs welded in both the passenger and driver header. I only need to use one. I remember thinking one side (maybe passenger) would be a super tight fit between installed sensor and firewall.

Not at home until Sunday. I can verify more when I’m near the bronco if you want. I don’t remember the cuts unfortunately! I think about an inch off the driver side header tube or crossover pipe. And a couple inches off the muffler outlet pipe I think to position the tailpipe. It pretty much rests on the transmission crossmember and this is the tightest fit. Not sure if that will prove to be a problem or not.

Duff was looking for guinea pigs about two weeks after I bought this setup. If I hadn’t already purchased, I definitely would’ve considered giving their kit and headers a try.

thanks, I think I will try and talk to monster mike. and see what they recommend. I am going to wait to make the call until I am ready to order which will be in a couple weeks once I get the engine trans and transfer case in place. in the mean time the bronco hut still looks like a good option. thanks for the info and the pictures.

 

[mustanggarage]

Here is what I did. 351W with NV3550. Wh Long tube headers, Magnaflow muffler and Summit tubing. Custom cut and welded in the garage. Had to clearance for the Clutch linkage. Otherwise I love it.

looks good thanks

 

[SDBMtber]

One other thing I forgot to mention. Bronco hut exhaust wants to crossover right in front of bell housing in the little “notch” provided by some oil pans.

I think I have the truck 351 oil pan which has that notch, but has less clearance to Front axle. Sounds like this plan will end up getting some clearance made by the axle into he oil pan under full compression!

Seems like the generally preferred 351 pan is the ford motorsports pan that has more middle clearance for the axle. But, this pan doesn’t have the notch where the bronco hut exhaust routes...

So my current plan is keep this pan. If the axle bumps end up being too bad, I’ll probbaly try and modify a notch into the ford motorsports pan or do a minor exhaust reroute to use that pan.

 

[mustanggarage]

good to know, I have the ford motorsport pan from wildhorses